Sapphire is a precious gemstone, primarily known for its rich blue color, although it can be found in a variety of colors, such as yellow, pink, and green. It is a variety of the mineral corundum, the same family as rubies, and is made of aluminum oxide. The blue color of sapphire comes from trace amounts of iron and titanium in its crystal structure.

Sapphires are highly valued for their durability, ranking 9 on the Mohs scale of hardness, making them second only to diamonds in terms of hardness among gemstones. This makes them ideal for use in jewelry, especially in engagement rings. The gemstone's clarity, brilliance, and wide range of colors also add to its appeal. Sapphire is often associated with wisdom, nobility, and divine favor, and has historically been a symbol of royalty and power.

The most famous sapphires come from regions such as Sri Lanka, Kashmir, and Myanmar, though sapphires are also found in other parts of the world. Some sapphires, especially from Kashmir, are highly prized for their deep, velvety blue hue, while others may show unique color-changing properties, especially under different light conditions.